I want to create a new software to control the motion of my Orion/Merlin/Skywatcher with the specific needs of recording motion controlled time-lapse.

I know there is the timelapse preset generator for papywizard but I feel its cumbersome and limiting so I started writing my own application.

What I already have: A cross platform Java application with the class to send serial commands to my head. I can rotate all axes at any speed.There is some excellent documentation about the serial protocol here: http://www.papywizard.org/wiki/DevelopGuide#MerlinOrionprotocol though I found some incomplete parts like the speed ratio with the "G" command.

I am also not quite sure yet which value corresponds to which speed as in the command sequence:

L<axis>G<axis>3<dir>I<axis>220000J<axis>

The "3" is the speed ratio and can actually also be 1 for slow and 4 for slew and the "I<axis>220000" (as found out with trial and error) command can take any value between 100000 and FF0000.4 for slew had some inconsistent behaviour and with no combination of values I was able to get the head to turn as slow as with the handcontrol in guide mode...

What I want to achieve:Allow full custom curve movements on both axis with a nice GUI to draw curves, preview motion, etc.

The plan is to release everything as open source (GNU GPL V3).

Any help with coding or more details about the serial protocol would be greatly appreciated.

I believe that all of you have interest in sharing a maximum of informations about Timelapse.Please make your code availlable somewhere in the spirit of "open source".Fréderic have show THE EXEMPLE with Papywizard.

I will say that more then 40 % of the "Papywizard" users are also interested in Timelapse, but the informations are so scatered.

To Frederic, is that not time to create a "dedicated part" for Timelapse into the Papywizard area ?What do-you thinck about ?

SpeedFor continuous movement there seem to be only 2 speed modes/ratios available each with 255 speed settings.

"Slow" goes from 2.16 degrees per minute to 28.08 degrees per minute

"Fast" goes from 56 degrees per minute to 245 degrees per minute

The "Slew" Mode is only good for the GOTO commands which I did not get into yet.

There also seems to be an even slower "track/guide" mode which is available on the handcrontrol but I did not find out yet how to use this mode from the serial interface

MotionIf you just want continous motion with a constant custom speed you can start the motion from the software and then disconnect the cable (and turn off your computer). The head will not stop movement when you unplug the cable.

This is what the program currently looks like:

Last edited by Sebastian on Fri Apr 29, 2011 1:16 pm, edited 1 time in total.

The good news is that the integrated GOTO controller seems to be pretty accurate. Average stepping error is around 0.01°. More accuracy could be achieved by moving the head "manually" with the speed commands and constantly checking the step position and adjusting speed accordingly. With this approach it would take longer to reach the GOTO position but we might be able to get the error down even further.

This does not say much about the real physical motion error due to mechanical components of the head, this is purely about the motion of the motor as measured by the optical encoder.

I looked for a good name for the software before registring for a google code repository and settled for "Chronomotion", I hope you like the name, I dont think Google offers the option to change it...

claudevh wrote:I have seen in your code that "COM1" is hard coded, thats OK ... I have changed to COM port of my BT device no problem but I don't get any connection ...How do you have connected the Merlin head to your PC, wired (TTL 5V convertor like the FTDI) or not wired like the "PapyMerlin" Bluetooth ???

I now added auto COM port discovery, so it should automatically list all detected COM ports. If the bluetooth adapter also creates a virtual COM port it should also be listed just like the hardwired ones.

I have tested the binary for Windows ... and it work !!! No problem till now !The "wired connection" via a "USB to TTL convertor" is OK.A "Virtual Serial" connection via BT can't be used at this moment.

I have some difficulties with how to use it all ...A small description of the functionalities will be welcome.